Merge branch 'for-linus-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad...
[linux-2.6-microblaze.git] / arch / powerpc / kernel / setup-common.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Common boot and setup code for both 32-bit and 64-bit.
4  * Extracted from arch/powerpc/kernel/setup_64.c.
5  *
6  * Copyright (C) 2001 PPC64 Team, IBM Corp
7  */
8
9 #undef DEBUG
10
11 #include <linux/export.h>
12 #include <linux/string.h>
13 #include <linux/sched.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/reboot.h>
17 #include <linux/delay.h>
18 #include <linux/initrd.h>
19 #include <linux/platform_device.h>
20 #include <linux/seq_file.h>
21 #include <linux/ioport.h>
22 #include <linux/console.h>
23 #include <linux/screen_info.h>
24 #include <linux/root_dev.h>
25 #include <linux/notifier.h>
26 #include <linux/cpu.h>
27 #include <linux/unistd.h>
28 #include <linux/serial.h>
29 #include <linux/serial_8250.h>
30 #include <linux/percpu.h>
31 #include <linux/memblock.h>
32 #include <linux/of_platform.h>
33 #include <linux/hugetlb.h>
34 #include <asm/debugfs.h>
35 #include <asm/io.h>
36 #include <asm/paca.h>
37 #include <asm/prom.h>
38 #include <asm/processor.h>
39 #include <asm/vdso_datapage.h>
40 #include <asm/pgtable.h>
41 #include <asm/smp.h>
42 #include <asm/elf.h>
43 #include <asm/machdep.h>
44 #include <asm/time.h>
45 #include <asm/cputable.h>
46 #include <asm/sections.h>
47 #include <asm/firmware.h>
48 #include <asm/btext.h>
49 #include <asm/nvram.h>
50 #include <asm/setup.h>
51 #include <asm/rtas.h>
52 #include <asm/iommu.h>
53 #include <asm/serial.h>
54 #include <asm/cache.h>
55 #include <asm/page.h>
56 #include <asm/mmu.h>
57 #include <asm/xmon.h>
58 #include <asm/cputhreads.h>
59 #include <mm/mmu_decl.h>
60 #include <asm/fadump.h>
61 #include <asm/udbg.h>
62 #include <asm/hugetlb.h>
63 #include <asm/livepatch.h>
64 #include <asm/mmu_context.h>
65 #include <asm/cpu_has_feature.h>
66 #include <asm/kasan.h>
67
68 #include "setup.h"
69
70 #ifdef DEBUG
71 #include <asm/udbg.h>
72 #define DBG(fmt...) udbg_printf(fmt)
73 #else
74 #define DBG(fmt...)
75 #endif
76
77 /* The main machine-dep calls structure
78  */
79 struct machdep_calls ppc_md;
80 EXPORT_SYMBOL(ppc_md);
81 struct machdep_calls *machine_id;
82 EXPORT_SYMBOL(machine_id);
83
84 int boot_cpuid = -1;
85 EXPORT_SYMBOL_GPL(boot_cpuid);
86
87 /*
88  * These are used in binfmt_elf.c to put aux entries on the stack
89  * for each elf executable being started.
90  */
91 int dcache_bsize;
92 int icache_bsize;
93 int ucache_bsize;
94
95
96 unsigned long klimit = (unsigned long) _end;
97
98 /*
99  * This still seems to be needed... -- paulus
100  */ 
101 struct screen_info screen_info = {
102         .orig_x = 0,
103         .orig_y = 25,
104         .orig_video_cols = 80,
105         .orig_video_lines = 25,
106         .orig_video_isVGA = 1,
107         .orig_video_points = 16
108 };
109 #if defined(CONFIG_FB_VGA16_MODULE)
110 EXPORT_SYMBOL(screen_info);
111 #endif
112
113 /* Variables required to store legacy IO irq routing */
114 int of_i8042_kbd_irq;
115 EXPORT_SYMBOL_GPL(of_i8042_kbd_irq);
116 int of_i8042_aux_irq;
117 EXPORT_SYMBOL_GPL(of_i8042_aux_irq);
118
119 #ifdef __DO_IRQ_CANON
120 /* XXX should go elsewhere eventually */
121 int ppc_do_canonicalize_irqs;
122 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
123 #endif
124
125 #ifdef CONFIG_CRASH_CORE
126 /* This keeps a track of which one is the crashing cpu. */
127 int crashing_cpu = -1;
128 #endif
129
130 /* also used by kexec */
131 void machine_shutdown(void)
132 {
133         /*
134          * if fadump is active, cleanup the fadump registration before we
135          * shutdown.
136          */
137         fadump_cleanup();
138
139         if (ppc_md.machine_shutdown)
140                 ppc_md.machine_shutdown();
141 }
142
143 static void machine_hang(void)
144 {
145         pr_emerg("System Halted, OK to turn off power\n");
146         local_irq_disable();
147         while (1)
148                 ;
149 }
150
151 void machine_restart(char *cmd)
152 {
153         machine_shutdown();
154         if (ppc_md.restart)
155                 ppc_md.restart(cmd);
156
157         smp_send_stop();
158
159         do_kernel_restart(cmd);
160         mdelay(1000);
161
162         machine_hang();
163 }
164
165 void machine_power_off(void)
166 {
167         machine_shutdown();
168         if (pm_power_off)
169                 pm_power_off();
170
171         smp_send_stop();
172         machine_hang();
173 }
174 /* Used by the G5 thermal driver */
175 EXPORT_SYMBOL_GPL(machine_power_off);
176
177 void (*pm_power_off)(void);
178 EXPORT_SYMBOL_GPL(pm_power_off);
179
180 void machine_halt(void)
181 {
182         machine_shutdown();
183         if (ppc_md.halt)
184                 ppc_md.halt();
185
186         smp_send_stop();
187         machine_hang();
188 }
189
190 #ifdef CONFIG_SMP
191 DEFINE_PER_CPU(unsigned int, cpu_pvr);
192 #endif
193
194 static void show_cpuinfo_summary(struct seq_file *m)
195 {
196         struct device_node *root;
197         const char *model = NULL;
198         unsigned long bogosum = 0;
199         int i;
200
201         if (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_PPC32)) {
202                 for_each_online_cpu(i)
203                         bogosum += loops_per_jiffy;
204                 seq_printf(m, "total bogomips\t: %lu.%02lu\n",
205                            bogosum / (500000 / HZ), bogosum / (5000 / HZ) % 100);
206         }
207         seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
208         if (ppc_md.name)
209                 seq_printf(m, "platform\t: %s\n", ppc_md.name);
210         root = of_find_node_by_path("/");
211         if (root)
212                 model = of_get_property(root, "model", NULL);
213         if (model)
214                 seq_printf(m, "model\t\t: %s\n", model);
215         of_node_put(root);
216
217         if (ppc_md.show_cpuinfo != NULL)
218                 ppc_md.show_cpuinfo(m);
219
220         /* Display the amount of memory */
221         if (IS_ENABLED(CONFIG_PPC32))
222                 seq_printf(m, "Memory\t\t: %d MB\n",
223                            (unsigned int)(total_memory / (1024 * 1024)));
224 }
225
226 static int show_cpuinfo(struct seq_file *m, void *v)
227 {
228         unsigned long cpu_id = (unsigned long)v - 1;
229         unsigned int pvr;
230         unsigned long proc_freq;
231         unsigned short maj;
232         unsigned short min;
233
234 #ifdef CONFIG_SMP
235         pvr = per_cpu(cpu_pvr, cpu_id);
236 #else
237         pvr = mfspr(SPRN_PVR);
238 #endif
239         maj = (pvr >> 8) & 0xFF;
240         min = pvr & 0xFF;
241
242         seq_printf(m, "processor\t: %lu\n", cpu_id);
243         seq_printf(m, "cpu\t\t: ");
244
245         if (cur_cpu_spec->pvr_mask && cur_cpu_spec->cpu_name)
246                 seq_printf(m, "%s", cur_cpu_spec->cpu_name);
247         else
248                 seq_printf(m, "unknown (%08x)", pvr);
249
250         if (cpu_has_feature(CPU_FTR_ALTIVEC))
251                 seq_printf(m, ", altivec supported");
252
253         seq_printf(m, "\n");
254
255 #ifdef CONFIG_TAU
256         if (cpu_has_feature(CPU_FTR_TAU)) {
257                 if (IS_ENABLED(CONFIG_TAU_AVERAGE)) {
258                         /* more straightforward, but potentially misleading */
259                         seq_printf(m,  "temperature \t: %u C (uncalibrated)\n",
260                                    cpu_temp(cpu_id));
261                 } else {
262                         /* show the actual temp sensor range */
263                         u32 temp;
264                         temp = cpu_temp_both(cpu_id);
265                         seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n",
266                                    temp & 0xff, temp >> 16);
267                 }
268         }
269 #endif /* CONFIG_TAU */
270
271         /*
272          * Platforms that have variable clock rates, should implement
273          * the method ppc_md.get_proc_freq() that reports the clock
274          * rate of a given cpu. The rest can use ppc_proc_freq to
275          * report the clock rate that is same across all cpus.
276          */
277         if (ppc_md.get_proc_freq)
278                 proc_freq = ppc_md.get_proc_freq(cpu_id);
279         else
280                 proc_freq = ppc_proc_freq;
281
282         if (proc_freq)
283                 seq_printf(m, "clock\t\t: %lu.%06luMHz\n",
284                            proc_freq / 1000000, proc_freq % 1000000);
285
286         if (ppc_md.show_percpuinfo != NULL)
287                 ppc_md.show_percpuinfo(m, cpu_id);
288
289         /* If we are a Freescale core do a simple check so
290          * we dont have to keep adding cases in the future */
291         if (PVR_VER(pvr) & 0x8000) {
292                 switch (PVR_VER(pvr)) {
293                 case 0x8000:    /* 7441/7450/7451, Voyager */
294                 case 0x8001:    /* 7445/7455, Apollo 6 */
295                 case 0x8002:    /* 7447/7457, Apollo 7 */
296                 case 0x8003:    /* 7447A, Apollo 7 PM */
297                 case 0x8004:    /* 7448, Apollo 8 */
298                 case 0x800c:    /* 7410, Nitro */
299                         maj = ((pvr >> 8) & 0xF);
300                         min = PVR_MIN(pvr);
301                         break;
302                 default:        /* e500/book-e */
303                         maj = PVR_MAJ(pvr);
304                         min = PVR_MIN(pvr);
305                         break;
306                 }
307         } else {
308                 switch (PVR_VER(pvr)) {
309                         case 0x0020:    /* 403 family */
310                                 maj = PVR_MAJ(pvr) + 1;
311                                 min = PVR_MIN(pvr);
312                                 break;
313                         case 0x1008:    /* 740P/750P ?? */
314                                 maj = ((pvr >> 8) & 0xFF) - 1;
315                                 min = pvr & 0xFF;
316                                 break;
317                         case 0x004e: /* POWER9 bits 12-15 give chip type */
318                                 maj = (pvr >> 8) & 0x0F;
319                                 min = pvr & 0xFF;
320                                 break;
321                         default:
322                                 maj = (pvr >> 8) & 0xFF;
323                                 min = pvr & 0xFF;
324                                 break;
325                 }
326         }
327
328         seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n",
329                    maj, min, PVR_VER(pvr), PVR_REV(pvr));
330
331         if (IS_ENABLED(CONFIG_PPC32))
332                 seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy / (500000 / HZ),
333                            (loops_per_jiffy / (5000 / HZ)) % 100);
334
335         seq_printf(m, "\n");
336
337         /* If this is the last cpu, print the summary */
338         if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
339                 show_cpuinfo_summary(m);
340
341         return 0;
342 }
343
344 static void *c_start(struct seq_file *m, loff_t *pos)
345 {
346         if (*pos == 0)  /* just in case, cpu 0 is not the first */
347                 *pos = cpumask_first(cpu_online_mask);
348         else
349                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
350         if ((*pos) < nr_cpu_ids)
351                 return (void *)(unsigned long)(*pos + 1);
352         return NULL;
353 }
354
355 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
356 {
357         (*pos)++;
358         return c_start(m, pos);
359 }
360
361 static void c_stop(struct seq_file *m, void *v)
362 {
363 }
364
365 const struct seq_operations cpuinfo_op = {
366         .start  = c_start,
367         .next   = c_next,
368         .stop   = c_stop,
369         .show   = show_cpuinfo,
370 };
371
372 void __init check_for_initrd(void)
373 {
374 #ifdef CONFIG_BLK_DEV_INITRD
375         DBG(" -> check_for_initrd()  initrd_start=0x%lx  initrd_end=0x%lx\n",
376             initrd_start, initrd_end);
377
378         /* If we were passed an initrd, set the ROOT_DEV properly if the values
379          * look sensible. If not, clear initrd reference.
380          */
381         if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) &&
382             initrd_end > initrd_start)
383                 ROOT_DEV = Root_RAM0;
384         else
385                 initrd_start = initrd_end = 0;
386
387         if (initrd_start)
388                 pr_info("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
389
390         DBG(" <- check_for_initrd()\n");
391 #endif /* CONFIG_BLK_DEV_INITRD */
392 }
393
394 #ifdef CONFIG_SMP
395
396 int threads_per_core, threads_per_subcore, threads_shift __read_mostly;
397 cpumask_t threads_core_mask __read_mostly;
398 EXPORT_SYMBOL_GPL(threads_per_core);
399 EXPORT_SYMBOL_GPL(threads_per_subcore);
400 EXPORT_SYMBOL_GPL(threads_shift);
401 EXPORT_SYMBOL_GPL(threads_core_mask);
402
403 static void __init cpu_init_thread_core_maps(int tpc)
404 {
405         int i;
406
407         threads_per_core = tpc;
408         threads_per_subcore = tpc;
409         cpumask_clear(&threads_core_mask);
410
411         /* This implementation only supports power of 2 number of threads
412          * for simplicity and performance
413          */
414         threads_shift = ilog2(tpc);
415         BUG_ON(tpc != (1 << threads_shift));
416
417         for (i = 0; i < tpc; i++)
418                 cpumask_set_cpu(i, &threads_core_mask);
419
420         printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
421                tpc, tpc > 1 ? "s" : "");
422         printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
423 }
424
425
426 u32 *cpu_to_phys_id = NULL;
427
428 /**
429  * setup_cpu_maps - initialize the following cpu maps:
430  *                  cpu_possible_mask
431  *                  cpu_present_mask
432  *
433  * Having the possible map set up early allows us to restrict allocations
434  * of things like irqstacks to nr_cpu_ids rather than NR_CPUS.
435  *
436  * We do not initialize the online map here; cpus set their own bits in
437  * cpu_online_mask as they come up.
438  *
439  * This function is valid only for Open Firmware systems.  finish_device_tree
440  * must be called before using this.
441  *
442  * While we're here, we may as well set the "physical" cpu ids in the paca.
443  *
444  * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
445  */
446 void __init smp_setup_cpu_maps(void)
447 {
448         struct device_node *dn;
449         int cpu = 0;
450         int nthreads = 1;
451
452         DBG("smp_setup_cpu_maps()\n");
453
454         cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32),
455                                         __alignof__(u32));
456         if (!cpu_to_phys_id)
457                 panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
458                       __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));
459
460         for_each_node_by_type(dn, "cpu") {
461                 const __be32 *intserv;
462                 __be32 cpu_be;
463                 int j, len;
464
465                 DBG("  * %pOF...\n", dn);
466
467                 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
468                                 &len);
469                 if (intserv) {
470                         DBG("    ibm,ppc-interrupt-server#s -> %d threads\n",
471                             nthreads);
472                 } else {
473                         DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
474                         intserv = of_get_property(dn, "reg", &len);
475                         if (!intserv) {
476                                 cpu_be = cpu_to_be32(cpu);
477                                 /* XXX: what is this? uninitialized?? */
478                                 intserv = &cpu_be;      /* assume logical == phys */
479                                 len = 4;
480                         }
481                 }
482
483                 nthreads = len / sizeof(int);
484
485                 for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) {
486                         bool avail;
487
488                         DBG("    thread %d -> cpu %d (hard id %d)\n",
489                             j, cpu, be32_to_cpu(intserv[j]));
490
491                         avail = of_device_is_available(dn);
492                         if (!avail)
493                                 avail = !of_property_match_string(dn,
494                                                 "enable-method", "spin-table");
495
496                         set_cpu_present(cpu, avail);
497                         set_cpu_possible(cpu, true);
498                         cpu_to_phys_id[cpu] = be32_to_cpu(intserv[j]);
499                         cpu++;
500                 }
501
502                 if (cpu >= nr_cpu_ids) {
503                         of_node_put(dn);
504                         break;
505                 }
506         }
507
508         /* If no SMT supported, nthreads is forced to 1 */
509         if (!cpu_has_feature(CPU_FTR_SMT)) {
510                 DBG("  SMT disabled ! nthreads forced to 1\n");
511                 nthreads = 1;
512         }
513
514 #ifdef CONFIG_PPC64
515         /*
516          * On pSeries LPAR, we need to know how many cpus
517          * could possibly be added to this partition.
518          */
519         if (firmware_has_feature(FW_FEATURE_LPAR) &&
520             (dn = of_find_node_by_path("/rtas"))) {
521                 int num_addr_cell, num_size_cell, maxcpus;
522                 const __be32 *ireg;
523
524                 num_addr_cell = of_n_addr_cells(dn);
525                 num_size_cell = of_n_size_cells(dn);
526
527                 ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL);
528
529                 if (!ireg)
530                         goto out;
531
532                 maxcpus = be32_to_cpup(ireg + num_addr_cell + num_size_cell);
533
534                 /* Double maxcpus for processors which have SMT capability */
535                 if (cpu_has_feature(CPU_FTR_SMT))
536                         maxcpus *= nthreads;
537
538                 if (maxcpus > nr_cpu_ids) {
539                         printk(KERN_WARNING
540                                "Partition configured for %d cpus, "
541                                "operating system maximum is %u.\n",
542                                maxcpus, nr_cpu_ids);
543                         maxcpus = nr_cpu_ids;
544                 } else
545                         printk(KERN_INFO "Partition configured for %d cpus.\n",
546                                maxcpus);
547
548                 for (cpu = 0; cpu < maxcpus; cpu++)
549                         set_cpu_possible(cpu, true);
550         out:
551                 of_node_put(dn);
552         }
553         vdso_data->processorCount = num_present_cpus();
554 #endif /* CONFIG_PPC64 */
555
556         /* Initialize CPU <=> thread mapping/
557          *
558          * WARNING: We assume that the number of threads is the same for
559          * every CPU in the system. If that is not the case, then some code
560          * here will have to be reworked
561          */
562         cpu_init_thread_core_maps(nthreads);
563
564         /* Now that possible cpus are set, set nr_cpu_ids for later use */
565         setup_nr_cpu_ids();
566
567         free_unused_pacas();
568 }
569 #endif /* CONFIG_SMP */
570
571 #ifdef CONFIG_PCSPKR_PLATFORM
572 static __init int add_pcspkr(void)
573 {
574         struct device_node *np;
575         struct platform_device *pd;
576         int ret;
577
578         np = of_find_compatible_node(NULL, NULL, "pnpPNP,100");
579         of_node_put(np);
580         if (!np)
581                 return -ENODEV;
582
583         pd = platform_device_alloc("pcspkr", -1);
584         if (!pd)
585                 return -ENOMEM;
586
587         ret = platform_device_add(pd);
588         if (ret)
589                 platform_device_put(pd);
590
591         return ret;
592 }
593 device_initcall(add_pcspkr);
594 #endif  /* CONFIG_PCSPKR_PLATFORM */
595
596 void probe_machine(void)
597 {
598         extern struct machdep_calls __machine_desc_start;
599         extern struct machdep_calls __machine_desc_end;
600         unsigned int i;
601
602         /*
603          * Iterate all ppc_md structures until we find the proper
604          * one for the current machine type
605          */
606         DBG("Probing machine type ...\n");
607
608         /*
609          * Check ppc_md is empty, if not we have a bug, ie, we setup an
610          * entry before probe_machine() which will be overwritten
611          */
612         for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) {
613                 if (((void **)&ppc_md)[i]) {
614                         printk(KERN_ERR "Entry %d in ppc_md non empty before"
615                                " machine probe !\n", i);
616                 }
617         }
618
619         for (machine_id = &__machine_desc_start;
620              machine_id < &__machine_desc_end;
621              machine_id++) {
622                 DBG("  %s ...", machine_id->name);
623                 memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
624                 if (ppc_md.probe()) {
625                         DBG(" match !\n");
626                         break;
627                 }
628                 DBG("\n");
629         }
630         /* What can we do if we didn't find ? */
631         if (machine_id >= &__machine_desc_end) {
632                 pr_err("No suitable machine description found !\n");
633                 for (;;);
634         }
635
636         printk(KERN_INFO "Using %s machine description\n", ppc_md.name);
637 }
638
639 /* Match a class of boards, not a specific device configuration. */
640 int check_legacy_ioport(unsigned long base_port)
641 {
642         struct device_node *parent, *np = NULL;
643         int ret = -ENODEV;
644
645         switch(base_port) {
646         case I8042_DATA_REG:
647                 if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303")))
648                         np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03");
649                 if (np) {
650                         parent = of_get_parent(np);
651
652                         of_i8042_kbd_irq = irq_of_parse_and_map(parent, 0);
653                         if (!of_i8042_kbd_irq)
654                                 of_i8042_kbd_irq = 1;
655
656                         of_i8042_aux_irq = irq_of_parse_and_map(parent, 1);
657                         if (!of_i8042_aux_irq)
658                                 of_i8042_aux_irq = 12;
659
660                         of_node_put(np);
661                         np = parent;
662                         break;
663                 }
664                 np = of_find_node_by_type(NULL, "8042");
665                 /* Pegasos has no device_type on its 8042 node, look for the
666                  * name instead */
667                 if (!np)
668                         np = of_find_node_by_name(NULL, "8042");
669                 if (np) {
670                         of_i8042_kbd_irq = 1;
671                         of_i8042_aux_irq = 12;
672                 }
673                 break;
674         case FDC_BASE: /* FDC1 */
675                 np = of_find_node_by_type(NULL, "fdc");
676                 break;
677         default:
678                 /* ipmi is supposed to fail here */
679                 break;
680         }
681         if (!np)
682                 return ret;
683         parent = of_get_parent(np);
684         if (parent) {
685                 if (of_node_is_type(parent, "isa"))
686                         ret = 0;
687                 of_node_put(parent);
688         }
689         of_node_put(np);
690         return ret;
691 }
692 EXPORT_SYMBOL(check_legacy_ioport);
693
694 static int ppc_panic_event(struct notifier_block *this,
695                              unsigned long event, void *ptr)
696 {
697         /*
698          * panic does a local_irq_disable, but we really
699          * want interrupts to be hard disabled.
700          */
701         hard_irq_disable();
702
703         /*
704          * If firmware-assisted dump has been registered then trigger
705          * firmware-assisted dump and let firmware handle everything else.
706          */
707         crash_fadump(NULL, ptr);
708         if (ppc_md.panic)
709                 ppc_md.panic(ptr);  /* May not return */
710         return NOTIFY_DONE;
711 }
712
713 static struct notifier_block ppc_panic_block = {
714         .notifier_call = ppc_panic_event,
715         .priority = INT_MIN /* may not return; must be done last */
716 };
717
718 void __init setup_panic(void)
719 {
720         /* PPC64 always does a hard irq disable in its panic handler */
721         if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
722                 return;
723         atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
724 }
725
726 #ifdef CONFIG_CHECK_CACHE_COHERENCY
727 /*
728  * For platforms that have configurable cache-coherency.  This function
729  * checks that the cache coherency setting of the kernel matches the setting
730  * left by the firmware, as indicated in the device tree.  Since a mismatch
731  * will eventually result in DMA failures, we print * and error and call
732  * BUG() in that case.
733  */
734
735 #define KERNEL_COHERENCY        (!IS_ENABLED(CONFIG_NOT_COHERENT_CACHE))
736
737 static int __init check_cache_coherency(void)
738 {
739         struct device_node *np;
740         const void *prop;
741         bool devtree_coherency;
742
743         np = of_find_node_by_path("/");
744         prop = of_get_property(np, "coherency-off", NULL);
745         of_node_put(np);
746
747         devtree_coherency = prop ? false : true;
748
749         if (devtree_coherency != KERNEL_COHERENCY) {
750                 printk(KERN_ERR
751                         "kernel coherency:%s != device tree_coherency:%s\n",
752                         KERNEL_COHERENCY ? "on" : "off",
753                         devtree_coherency ? "on" : "off");
754                 BUG();
755         }
756
757         return 0;
758 }
759
760 late_initcall(check_cache_coherency);
761 #endif /* CONFIG_CHECK_CACHE_COHERENCY */
762
763 #ifdef CONFIG_DEBUG_FS
764 struct dentry *powerpc_debugfs_root;
765 EXPORT_SYMBOL(powerpc_debugfs_root);
766
767 static int powerpc_debugfs_init(void)
768 {
769         powerpc_debugfs_root = debugfs_create_dir("powerpc", NULL);
770
771         return powerpc_debugfs_root == NULL;
772 }
773 arch_initcall(powerpc_debugfs_init);
774 #endif
775
776 void ppc_printk_progress(char *s, unsigned short hex)
777 {
778         pr_info("%s\n", s);
779 }
780
781 void arch_setup_pdev_archdata(struct platform_device *pdev)
782 {
783         pdev->archdata.dma_mask = DMA_BIT_MASK(32);
784         pdev->dev.dma_mask = &pdev->archdata.dma_mask;
785 }
786
787 static __init void print_system_info(void)
788 {
789         pr_info("-----------------------------------------------------\n");
790         pr_info("phys_mem_size     = 0x%llx\n",
791                 (unsigned long long)memblock_phys_mem_size());
792
793         pr_info("dcache_bsize      = 0x%x\n", dcache_bsize);
794         pr_info("icache_bsize      = 0x%x\n", icache_bsize);
795         if (ucache_bsize != 0)
796                 pr_info("ucache_bsize      = 0x%x\n", ucache_bsize);
797
798         pr_info("cpu_features      = 0x%016lx\n", cur_cpu_spec->cpu_features);
799         pr_info("  possible        = 0x%016lx\n",
800                 (unsigned long)CPU_FTRS_POSSIBLE);
801         pr_info("  always          = 0x%016lx\n",
802                 (unsigned long)CPU_FTRS_ALWAYS);
803         pr_info("cpu_user_features = 0x%08x 0x%08x\n",
804                 cur_cpu_spec->cpu_user_features,
805                 cur_cpu_spec->cpu_user_features2);
806         pr_info("mmu_features      = 0x%08x\n", cur_cpu_spec->mmu_features);
807 #ifdef CONFIG_PPC64
808         pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
809 #endif
810
811         print_system_hash_info();
812
813         if (PHYSICAL_START > 0)
814                 pr_info("physical_start    = 0x%llx\n",
815                        (unsigned long long)PHYSICAL_START);
816         pr_info("-----------------------------------------------------\n");
817 }
818
819 #ifdef CONFIG_SMP
820 static void smp_setup_pacas(void)
821 {
822         int cpu;
823
824         for_each_possible_cpu(cpu) {
825                 if (cpu == smp_processor_id())
826                         continue;
827                 allocate_paca(cpu);
828                 set_hard_smp_processor_id(cpu, cpu_to_phys_id[cpu]);
829         }
830
831         memblock_free(__pa(cpu_to_phys_id), nr_cpu_ids * sizeof(u32));
832         cpu_to_phys_id = NULL;
833 }
834 #endif
835
836 /*
837  * Called into from start_kernel this initializes memblock, which is used
838  * to manage page allocation until mem_init is called.
839  */
840 void __init setup_arch(char **cmdline_p)
841 {
842         kasan_init();
843
844         *cmdline_p = boot_command_line;
845
846         /* Set a half-reasonable default so udelay does something sensible */
847         loops_per_jiffy = 500000000 / HZ;
848
849         /* Unflatten the device-tree passed by prom_init or kexec */
850         unflatten_device_tree();
851
852         /*
853          * Initialize cache line/block info from device-tree (on ppc64) or
854          * just cputable (on ppc32).
855          */
856         initialize_cache_info();
857
858         /* Initialize RTAS if available. */
859         rtas_initialize();
860
861         /* Check if we have an initrd provided via the device-tree. */
862         check_for_initrd();
863
864         /* Probe the machine type, establish ppc_md. */
865         probe_machine();
866
867         /* Setup panic notifier if requested by the platform. */
868         setup_panic();
869
870         /*
871          * Configure ppc_md.power_save (ppc32 only, 64-bit machines do
872          * it from their respective probe() function.
873          */
874         setup_power_save();
875
876         /* Discover standard serial ports. */
877         find_legacy_serial_ports();
878
879         /* Register early console with the printk subsystem. */
880         register_early_udbg_console();
881
882         /* Setup the various CPU maps based on the device-tree. */
883         smp_setup_cpu_maps();
884
885         /* Initialize xmon. */
886         xmon_setup();
887
888         /* Check the SMT related command line arguments (ppc64). */
889         check_smt_enabled();
890
891         /* Parse memory topology */
892         mem_topology_setup();
893
894         /*
895          * Release secondary cpus out of their spinloops at 0x60 now that
896          * we can map physical -> logical CPU ids.
897          *
898          * Freescale Book3e parts spin in a loop provided by firmware,
899          * so smp_release_cpus() does nothing for them.
900          */
901 #ifdef CONFIG_SMP
902         smp_setup_pacas();
903
904         /* On BookE, setup per-core TLB data structures. */
905         setup_tlb_core_data();
906
907         smp_release_cpus();
908 #endif
909
910         /* Print various info about the machine that has been gathered so far. */
911         print_system_info();
912
913         /* Reserve large chunks of memory for use by CMA for KVM. */
914         kvm_cma_reserve();
915
916         klp_init_thread_info(&init_task);
917
918         init_mm.start_code = (unsigned long)_stext;
919         init_mm.end_code = (unsigned long) _etext;
920         init_mm.end_data = (unsigned long) _edata;
921         init_mm.brk = klimit;
922
923         mm_iommu_init(&init_mm);
924         irqstack_early_init();
925         exc_lvl_early_init();
926         emergency_stack_init();
927
928         initmem_init();
929
930         early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
931
932         if (IS_ENABLED(CONFIG_DUMMY_CONSOLE))
933                 conswitchp = &dummy_con;
934
935         if (ppc_md.setup_arch)
936                 ppc_md.setup_arch();
937
938         setup_barrier_nospec();
939         setup_spectre_v2();
940
941         paging_init();
942
943         /* Initialize the MMU context management stuff. */
944         mmu_context_init();
945
946         /* Interrupt code needs to be 64K-aligned. */
947         if (IS_ENABLED(CONFIG_PPC64) && (unsigned long)_stext & 0xffff)
948                 panic("Kernelbase not 64K-aligned (0x%lx)!\n",
949                       (unsigned long)_stext);
950 }